An antihypertensive factor in the erythrocytes of essential hypertensive subjects--effects on blood pressure and calcium uptake by vascular tissue in rats

An extract prepared from the erythrocytes of essential hypertensive subjects was found to significantly lower systolic blood pressure (SBP) in spontaneously (SHR) and renal hypertensive rats (RHR) following a single intravenous or intraperitoneal injection: The maximum SBP reduction was 42.8 mmHg in SHR and 38.3 mmHg in RHR. In contrast, this hypertensive factor (AHF) had little effect on normotensive Wistar Kyoto and Wistar rats. AHF was also found to significantly suppress Ca2+ uptake by vascular smooth muscle in the mesenteric artery and aorta of hypertensive and normotensive rats (P less than 0.05, respectively). Furthermore, AHF prepared from the erythrocytes of normotensive subjects was shown to have a similar effect.

[Radioimmunoassay of serum myelin basic protein]

Using purified human brain myelin basic protein (MBP) to raise antiserum in rabbits and to prepare 125I-labelled MBP (chloramine-T method), We have established a high specific, precise and sensitive double-antibody radioimmunoassay for the measurement of human serum MBP. The sensitivity was 0.5 ng/ml. In the present study, the serum samples of thirty patients with various neurological diseases were detected. An important clinical implication is that serum MBP level should serve as an index for the damage degree of central neurological diseases.

Evidence of an EGF/TGE-alpha--independent pathway for estrogen-regulated cell proliferation

To elucidate the relationship between epidermal growth factor (EGF)/transforming growth factor (TGF-alpha) and estradiol-17 beta (E) in cell proliferation, we examined their effects on the breast cancer cell line, CAMA-1. While E was able to consistently induce cell proliferation under a variety of experimental conditions, EGF/TGF-alpha was without effect. Despite the presence of the receptor (EGFR) gene, mature EGFR protein and mRNA were not detected by radioreceptor assay, 35S Met-labelling, and the Intron Differential RNA/PCR method under conditions in which cells remain responsive to E. Furthermore, TGF-alpha is not an autocrine factor in CAMA-1 cells. We demonstrated unequivocally that EGF/TGF-alpha interaction with EGFR is not an obligatory event in mediating estrogen-stimulated cell proliferation.

A fluorinated 2-nitroimidazole, KU-2285, as a new hypoxic cell radiosensitizer

To develop new hypoxic cell radiosensitizers, we incorporated fluorine atoms into the side chain of the 2-nitroimidazole. Of the resulting compounds, KU-2285 (a 2-nitroimidazole with an N1-substituent of CH2CF2CONHCH2-CH2OH) was considered the most useful as a hypoxic cell radiosensitizer. In this study, its in vivo radiosensitizing activity and acute toxicity were compared with those of etanidazole. The reduction potentials of KU-2285 and etanidazole were -0.96 V and -1.05 V vs Ag/Ag+ in N,N-dimethylformamide, respectively, and their respective octanol/water partition coefficients were 0.25 and 0.040. The in vivo radiosensitizing activity of KU-2285 was found to be similar to that of etanidazole at the same administration dose when assayed by an in vivo-in vitro assay, a growth delay assay, and a tumor control assay using SCC VII tumor or transplanted mammary tumor in C3H/He mice. Although the radiosensitizing activity of etanidazole was reduced when it was administered orally, there was no significant difference in the radiosensitizing activity of KU-2285 whether it was administered intravenously, intraperitoneally, or orally. The acute toxicity measured as the LD50/7 in 8-week-old female C3H/HeJ mice was found to be 2.4 g/kg (intravenously), 2.1 g/kg (intraperitonealy), and 4.25 g/kg (orally) for KU-2285, whereas it was 4.75 g/kg (intravenously) for etanidazole.

Reproductive factors and colorectal cancer risk among Chinese females

We report results from a population-based case-control study of colorectal cancer among Chinese women in western North America (NA) and the People's Republic of China (China). A common protocol was used to assess reproductive characteristics and hormone use of 395 Chinese women (189 from NA and 206 from China) with cancer of the colon or rectum and of 1112 age-matched Chinese controls (494 from NA and 618 from China). In NA, risks for cancers of both the colon and rectum were lower among parous compared to nulliparous women (odds ratio for colorectal cancer, 0.6, P = 0.08), but the trend in risk was not smooth with increasing number of livebirths. This association with parity was absent for both cancer sites in China. There were no consistent patterns in the relationships between other reproductive factors (including age at menarche, age at first livebirth, menopausal status) and risk of colon and rectal cancer on either continent.

[Status of Yunnan drug banxia and its botanical origin]

L. Yunnan, the medicinal material Banxia recorded in The Pharmacopoeia of the People's Republic of China (1985 ed.) is called "Dizhu Banxia" (stem tuber of Pinellia ternata). Besides, "Shanzhu Banxia" (stem tuber of Arisaema yunnanense, A. bathycoleum, A. saxatile and A. prazeri) is also used medically as Banxia, while "Gouzhua Banxia" (stem tuber of Arisaema franchetianum, A. likiangense and Pinellia pedatisecta) is not.

Purification of Trypanosoma cruzi surface proteins involved in adhesion to host cells

We have identified four surface 83 kDa proteins of pI values 6.3, 6.4, 6.5 and 6.6 in T. cruzi trypomastigotes which specifically bind to rat heart myoblasts. These proteins were purified by isoelectric focusing and anion-exchange chromatography in an FPLC system. These 83 kDa proteins inhibit the attachment of trypomastigotes to myoblasts in a concentration-dependent manner, indicating that these trypomastigote proteins mediate the attachment of trypomastigotes to heart myoblasts.

[Inhibitory effect of secretin on gastric motility in isolated vascular perfused rat stomach]

Effect of secretin on gastric motility was studied on the preparation of isolated vascular perfused rat stomach. The results showed: (1) Secretin markedly inhibited spontaneous as well as pentagastrin stimulated antral motility. (2) Antisecretin serum completely abolished the inhibitory effect of secretin on antral motility. (3) Antisomatostatin serum and indomethacin blocked the inhibitory effect on antral motility induced by secretin. The results indicated that the inhibitory effect of secretin might be produced through direct action of secretin on secretin receptors and mediated partially by the local somatostatin and prostaglandin in gastric antrum.

[The measurement of p30 level in the normal human seminal plasma by the Beckman immunochemistry system using anti-30 serum]

This paper is the first report about the measurement of p30 level in the normal human seminal plasma by the Beckman immunochemistry system (ICS) using anti-p30 serum. The p30 levels of 108 samples of normal human seminal plasma were measured. The range of p30 level was 0.2996-4.3913 mg/ml. The square root transformation statistical analysis indicated that the coefficient of skewness was 0.0237 the coefficient of kurtosis was -0.8854, the p30 level in normal human seminal plasma fitted the square root normal distribution, the mean was 1.6236 mg/ml and the standard deviation was 0.1641 mg/ml.

[Anti-anaphylactic pharmacological action of water-soluble constituents of Ginkgo biloba L. episperm]

Water-soluble constituents of Ginkgo biloba episperm 100 or 200 mg/kg po given to mice inhibited passive cutaneous allergic response and the same dose given to rats ip inhibited mast cell degranulation. It antagonized the contractile effect of isolated guinea pig ileum smooth muscles induced by the antigen. It inhibited the deliverance of SRS-A from anaphylactic lung of guinea pig.

Diet, physical activity, and colorectal cancer among Chinese in North America and China

In a population-based case-control study of colorectal cancer among Chinese men and women in western North America and the People's Republic of China, a common protocol was used to assess past life-style characteristics of 905 cases diagnosed during 1981-1986 and 2,488 controls. Risks for cancers of both the colon and rectum increased with increased food energy from fat, protein, carbohydrate, and all energy sources combined, for both sexes and on both continents. Yet, in multivariate analysis, colorectal cancer risk was significantly associated only with saturated fat; no relationships were seen with other dietary sources of energy. Colon cancer risk was elevated among men employed in sedentary occupations. On both continents and in both sexes, risks for cancers of both the colon and rectum increased with increasing time spent sitting. Further, the association between colorectal cancer risk and saturated fat was stronger among the sedentary than among the active. Risk among sedentary Chinese Americans of either sex increased more than fourfold from the lowest to the highest category of saturated fat intake. Among migrants to North America, risk increased with increasing years lived in North America. These observations suggest (a) that colorectal cancer risk increases with duration of exposure to a sedentary life-style and a diet rich in saturated fat; (b) that higher incidence among Chinese-American men relative to women is due to longer duration of these habits among men, who have lived longer in North America; and (c) that higher risk among Chinese Americans of both sexes relative to risk among the general population in China is due to differences in such habits. Attributable risk calculations suggest that, if these associations are causal, saturated fat intakes exceeding 10 g/day, particularly in combination with physical inactivity, could account for 60% of colorectal cancer incidence among Chinese-American men and 40% among Chinese-American women.

[Sedative-hypnotic effect of caulis Polygoni multiflori decoction]

The sedative-hypnotic effect of Caulis Polygoni multiflori decoction (CPMD) was studied by the rolling cylinder method in mice and by the somnopolygraphic recording method in rats. The result from the rolling method in mice showed that CPMD (9g/kg) did have synergic action with the subthreshold hypnotic dose of sodium pentobarbital (20mg/kg). The result from the somnopolygraphic recording experiment showed that the immediate hypnotic effect of an effective dose of CPMD (20g/kg) was basically similar to that of diazepam (5mg/kg) used under the same experimental condition, chiefly an increase in the duration of slow wave sleep phase (SWS) and a decrease in the duration of paradoxical sleep phase (PS). By the end of a three-day session in dose of twice a day the hypnotic effect appeared more prominent and the reduction of SWS latency became significant.

KIH-802, an acetohydroxamic acid derivative of 2-nitroimidazole, as a new potent hypoxic cell radiosensitizer: radiosensitizing activity, acute toxicity, and pharmacokinetics

The radiosensitizing activity, acute toxicity, and pharmacokinetics of a new hypoxic cell radiosensitizer, potassium 2-nitroimidazole-1-acetohydroxamate (KIH-802), were compared with those of misonidazole (MISO) and etanidazole (SR-2508). The radiosensitizing activity of KIH-802 was slightly higher than that of MISO and SR-2508 in vitro and was similar to or slightly higher than that of MISO or SR-2508 in vivo. The acute toxicity of KIH-802 was slightly higher than that of MISO. The concentrations of KIH-802 in the brains and peripheral nerves of mice were as low as those of SR-2508 and lower than those of MISO.

A family of positive regulators related to the Pseudomonas putida TOL plasmid XylS and the Escherichia coli AraC activators

The XylS family consists of a least 8 different transcriptional regulators. Six of these proteins are positive regulators for the catabolism of carbon sources (benzoate and sugars) in Escherichia coli, Pseudomonas putida and Erwinia carotovora, and two of them are involved in pathogenesis in Escherichia coli and Yersinia enterocolitica. Based on protein alignments, the members of this family exhibit a long stretch of homology at the C-terminal end. The regulators involved in the catabolism of carbon sources stimulate transcription from their respectively regulated promoters only in the presence of effectors. In two of the regulators, mutations at the non-homologous N-terminus alter affinity and specificity for effectors while mutations at the conserved C-terminus part decrease activation of transcription from their corresponding regulated promoters. It is thus probable that the variable N-terminus end in this family of regulators contains the motif involved in effector recognition, while the C-terminal end is involved in DNA-binding. These proteins seem to be related by common ancestry and may act through similar mechanisms of positive regulation effected through similar folding patterns.

Supplementary iodine fails to reverse hypothyroidism in adolescents and adults with endemic cretinism

The efficacy of supplemental iodine in correcting hypothyroidism in adults and older children with endemic myxedematous cretinism is not known. To investigate this issue we administered im iodized oil (1.5 mL) to 28 hypothyroid endemic cretins (TSH, greater than 5 mIU/L) from western China, aged 14-52 yr (mean = 29 SD = 11 yr). Clinical examination, intelligence testing (Hiskey Nebraska Test of Learning Aptitude and the Griffiths Mental Development Scales), and thyroid function tests were performed before and 6 months after iodine supplementation. We found that signs of thyroid hormone deficiency, dwarfism, and delayed sexual maturity persisted after iodine supplementation. Further, mental disability and other clinical features of neurological damage were not altered by treatment. The mean serum concentration of total T4 before treatment was 75 nmol/L (SD = 40) and fell after iodized oil administration to 56 nmol/L (SD = 29; P less than 0.001). Mean serum levels of TSH before and after iodine showed a paradoxical fall [85 mIU/L (SD = 102) and 46 mIU/L (SD = 46), respectively]. Serum TSH levels decreased into the normal range (less than 5 mIU/L) in only 1 of 28 patients (4%). We conclude that iodine supplementation does not reverse thyroid hormone deficiency or its sequelae in adolescents and adults with endemic myxedematous cretinism. Iodized oil in this age group of patients with endemic cretinism does not appear to be beneficial and should be used with caution.

An important role of endogenous insulin on exocrine pancreatic secretion in rats

We have investigated a physiological role of endogenous insulin on exocrine pancreatic secretion stimulated by a liquid meal as well as exogenous secretin and cholecystokinin octapeptide (CCK-8) in conscious rats. Each rat was prepared with a chronic pancreatic fistula and an indwelling catheter in a jugular vein. Oral ingestion of a liquid meal (5 ml) resulted in significant increases in pancreatic secretion, including volume, bicarbonate, and amylase output, in these rats. A rabbit anti-insulin serum (1.0 ml) given intravenously completely blocked the postprandial exocrine pancreatic secretion, whereas a normal rabbit serum did not influence the pancreatic secretion in the same rats. When pancreatic secretion was stimulated by intravenous administration of both secretin and CCK-8 in three different doses, including 0.015, 0.03, and 0.06 clinical unit and microgram.kg-1.h-1, respectively, volume, bicarbonate, and amylase output increased significantly in a dose-dependent manner. This increase in pancreatic secretion was also completely blocked by a rabbit anti-insulin serum, whereas it was not influenced by a normal rabbit serum. The amount of the antiserum employed abolished the postprandial increases in plasma insulin concentration. We conclude that endogenous insulin plays an important role on the regulation of postprandial pancreatic secretion in rats. Furthermore, for the stimulatory action of the two intestinal hormones secretin and CCK-8 on the pancreatic exocrine secretion, endogenous insulin is need.

[Short-term curative effect of cultured Cordyceps sinensis (Berk.) Sacc. Mycelia in chronic hepatitis B]

33 cases of chronic hepatitis B. patients treated with cultured Cordyceps sinensis mycelia have shown that the drug improves the liver function, promotes negative transfer HBsAg, and markedly helps to raise plasma albumin, resist high gamma globulin and to adjust body immunocompetence. It is therefore suggested that cultured Cordyceps sinensis mycelia may be used as a medicine for chronic hepatitis B. patients in adjusting protein metabolism and correcting inversion of albumin and globulin.

[Effects of CCK-8 of hypothalamus on antral motility in rats]

Cholecystokinin-octapeptide (CCK-8) of 10 ng were injected into lateral hypothalamus (LH) and ventromedial hypothalamus (VMH) in conscious rats, both of which brought about inhibition of antral motility recorded by a strain gauge, the actions were partly antagonised by bilateral vagotomy, but blocked by intravenous infusion of atropine or regitine. It is suggested that both vagus and sympathetic nerves be involved in mediation of function of central CCK-8. In addition, the unit spontaneous discharges of neurons in vagal nuclei were attenuated while CCK-8 injected into LH. On the contrary, the antral motility was stimulated markedly by injection CCK-8-antiserum into LH, indicating that the endogenous CCK-8 in this area exercises a continuous restraint on antral motility in the basal state. CCK-8 cells both in LH and VMH were visualized by PAP method. It may be reasonable to refer this as the histological basis of the identical function on antral motility exercised by CCK-8 both in LH and VMH.

[Inhibition of gastric acid secretion by vascularly perfused secretin and somatostatin in isolated rat stomach]

Effects of secretin and somatostatin on acid secretion and its relation to prostaglandin E, I2 release in the totally isolated vascularly perfused rat stomach were studied. The results showed: (1) Secretin and somatostatin both markedly inhibited acid secretion stimulated by pentagastrin. Indomethacin could reverse the inhibitory effects of acid secretion by secretin and somatostatin. (2) Secretin increased PGE and PGI2 metabolite 6-Keto-PGF1 alpha release significantly. Somatostatin only increased PGE release. Indomethacin could block stimulatory affects of secretin on PGE, 6-Keto-PGF1 alpha release and somatostatin on PGE release. These results indicated that: (1) inhibition of acid secretion by secretin was mediated by PGI2 and PGE release; (2) inhibition of acid secretion by somatostatin was mediated only by PGE release.

A new, potent 2-nitroimidazole nucleoside hypoxic cell radiosensitizer, RP170

The radiosensitizing activity, acute toxicity and pharmacokinetics of RP170, a new hypoxic cell radiosensitizer, were compared with those of misonidazole (MISO) and SR2508. RP170 belongs to the group of 2-nitroimidazole nucleosides, which are designed to be selectively excluded from the neural tissue. The reduction potential of RP170 was similar to that of MISO and SR2508. The partition coefficients in octanol/water of RP170, MISO, and SR2508 were 0.094, 0.35, and 0.021, respectively. The radiosensitizing activity of RP170 was similar to that of MISO and SR2508 in vitro and in vivo. There was no significant difference in the radiosensitizing activity of RP170 in vivo between intravenous and intraperitoneal administration. The acute toxicity of RP170 was the same as that of SR2508. Pharmacokinetic evaluation showed that the concentration of RP170 in the brain was as low as that of SR2508. RP170 is expected to have the same radiosensitizing effects as MISO and SR2508, and to be less neurotoxic than MISO.